Julia is purchasing a home. She is in the $32\%$ marginal tax bracket. After making a $$150,000$ down payment, she will need to borrow $$500,000$ to close the deal. Her investment advisor suggests that rather than seeking a conventional mortgage $($currently at $5\mathrm{.}25\%),$ she should borrow the funds from her brokerage firm using the value of her portfolio as collateral. This alternative is called a margin loan which currently has a $4\%$ rate. Since the rate is lower, Julia is really interested. However, she wants to run this idea by you, her tax advisor, before making a decision.

a$.$ What is your recommendation and why?

b$.$ Support your recommendation with primary sources.